In this study, we tried to develop IFN-γ gene therapy by a replication defective adenovirus encoding the human IFN-γ (Ad-IFNγ) on nasopharyngeal carcinoma (NPC), our results showed Ad-IFNγ effectively expressed in NPC cells, significantly inhibited tumor cell proliferation and induced cell apoptosis in vitro, inhibited the growth of xenografts in nude mice. The gene discussed is IFNG; the disease is neoplasm.